well..i'll give you an engineering answer...
your car relies on the viscosity of the oil along with speed the rotating parts move for protection. I barrier is formed between the bearing and the wearing surface when it reaches higher rotating speeds.
When sitting idle... (rotation is slow) the barrier slowly depletes until the engine teperature rises to it's maximum idled temperature. I'm not sure exactly what it is for BMW, but i'm guessing around 230°F. When this max temp is reached, the oil's viscoty is the lowest....or in other words the oils is thinner (like water)
sitting at idle for a long time.... only increases the ammount of wear on the bearing surfaces. Your car should not overheat.... only wear its parts faster.
You could probably idle through 10 tanks of gas and not notice any difference. You however, may lose about 10K miles off the life of your engine.
hope this helps a little.
your car relies on the viscosity of the oil along with speed the rotating parts move for protection. I barrier is formed between the bearing and the wearing surface when it reaches higher rotating speeds.
When sitting idle... (rotation is slow) the barrier slowly depletes until the engine teperature rises to it's maximum idled temperature. I'm not sure exactly what it is for BMW, but i'm guessing around 230°F. When this max temp is reached, the oil's viscoty is the lowest....or in other words the oils is thinner (like water)
sitting at idle for a long time.... only increases the ammount of wear on the bearing surfaces. Your car should not overheat.... only wear its parts faster.
You could probably idle through 10 tanks of gas and not notice any difference. You however, may lose about 10K miles off the life of your engine.
hope this helps a little.
